Method



J. SCHAEFER- METHOD OF AND APPARATUS FOR MAKING HOLLOW RUBBER ARTICLESApril 19 1927.

Filed June 28, 1924 5 Sheets-Sheet 1 FIG *1 I N VENTOR IQ, 7174 65, ATTORNEY.

April 19, 1927. 1,5 ,399

J. SCHAEFER I METHOD OF AND APPARATUS FOR MAKING HOLLO W RUBBER ARTICLESFiled June 28, 1924 5 Sheets-Sheet JIVTAEQVTOB April 19 1927.

J. SCHAEFER METHOD OF AND APPARATUS FOR MAKING HOLLOW RUBBER ARTICLESFiled June 28, 1924 5 Sheets-Sheet 3 QZJV mam/rai April 19, 1927.

- J. SCHAEFER -METHOD OF AND APPARATUS FOR MAKING HOLLOW RUBBER ARTICLESil June 28. 1924 5 Sheets-Sheet 4 JNME'NrQZZ 3' 7 we QKMAJQAQQflTZ'OZENEi S A April 19, 1927.

v 1,625,399 J. SCHAEFER METHQD OF AND APPARATUS FOR MAKING HOLLOW RUBBERARTICLES Filed June 28, 1924 5 Sheets-Sheet 5 Inrvmvr OR HTZORNEYJ ill)Patented Apr, l9,

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JAMES SCI'IAEFER. OF YONKERS, NEVT YORK, ASEJGNOR TO PABAMDUNT RUBBERCON- SOLIDATED INC., A CQRPQH-ATION F DELAWARE.

METHOD (D? AND APPARATUS FOR MAKING HOLLOW? RUBBER ARTICLES.

Application filed June 28, 1924. Serial No. 722,986.

This invention relates to a method of and apparatus for making hollowrubber arti cles having certain portions or regions thereof o'll sctfrom other portions or regions, such as rubber toy animals and siini larobjects.

In making rubber toy objects, for instance, animals where there are legsoft-set from a plane passing through the mid-portion of the animal, theusual. practice heretoit'ore has been to form the opposing halves andthen to cement the halves prior to vnloanization. One of the.di'tficnlties o't joininn two halves of rubber to animal in thevulcanizinglf process has been due to the :tact that the body hasusually been died out between male and female dies and semicured to holdits shape until vulcanized, and the S'Glnlfillll'lllflf interferes withsatisfactorily securing the parts together. Moreover, the operation iscmnparatively slow and expensive, and the initial expense or matchingmale and female dies is considerable.

The object 01" my invention is to provide 'l'or )neiu'naticall v forminghollow rubber objects, of the character set forth, so as to elin'iinatethe necessity for pressing the halres between male and female dies, andto enable ecoi'iolnical and rapid operation.

I carry out the above object by using a two part :tfori'ning mold soarrangel'l that the iililierent cavities therein (the. legs of theanimal. for instance) lie side by side though in oll'set planes and areembraced by a continuous raised warped cutting edge which delines theperiphery of the biscuit. ".lhis cutting edge gradually diverges fromone plane to another ly an incline which is always materially less thannormal to the plane oi separation of the mold members, so thatthroughout its extent it has a cutting action when the two mold membersare brought together. The various projections oi? the biscuit, as torinstance the legs and cars oi? the animal are sutliciently distortedfrom the natural position so that the cutting" edge forms a continuouscircuit, never having one portion behind another, and always having: ahorimutal. component. The variation from a plane in one niold member isresponded to by complementary variation in the outer mold nieu'iber, sothat notwithstanding the cutting edges are out of a plane they meetthroughout, when the mold nielnbers are brought together.

Provision is made for pneumatically forcing raw rubber sheet stool: intothe cavities of the two mold n'ien'ibers and then these nien'ibers arebrought together to form a seam and cut off the surplus stock, thusu'ovlding a suitable biscuit. Before the junction, some suitable heatexpanding substance may be placed in the lined lower mold inen'iber,then, after the biscuit is torniel. it transferred to a properly shapedvulcanizing mold and l1eated.thereby gasifying the enclosed material,giving the. desired internal pressure. If desired, such gas may be ofpermanent nature and retained in the "forming article.

An apparatus tor carrying; out the above method is illustrated in thedrawings and set forth in the following description. My inventionincludes both the method and apparatus, and its essential features willbe summarized in the claims.

in the drawings, ll 1 is a plan of several forn'iing inenjihersresponding to this invention, mounted in a suitable holder or baskethaving a suction connection, whereby the cavities may be exhausted ofair. E is a plan of basket with the mold members remover. Figs. 3 and 4:are cross sections on the lines and l-lon lli 1. Fig. 5 is a bottom planof one 01: the tlt'orn'iing mold inei'i'ibers. Figs. 6 and 7 are laceplans of the two 'lorming lnold members, the particular cavities shownbeing; designed for the formation of a toy horse. 8 ant l) are faceplans of the corresponding valcaniaing molds. Figs. 10 and 11, areperspectives of the two "forming molds shown in plan in 6 and 7. Figs.1.2 and 13 are perspectives of the two vulanizing molds shown in plan inFigs. 8 and 9, Fig. i l is a view of the biscuit l orined by the n'iolds0]. Figs. 6 and 7 or 10 and 11. Fig. 15 is a sectional view oi the twotoriuing molds separating, but in proper vertical position for coaction,the plane of the section being indicated by the line 15-15 on Figs. 6and 7. Fig. 16 is a corresponding section of the corre sponding'vulcanizing mold, the plane of the section, being indicated b the line16-16 section of the vulcanizing mold correspond- Ill toy articlecomprisesthepneumatic [formation of a biscuit in a peculiar formingmold, then the transferring of the biscuit to a suitably shapedvulcanizing mold against the wall of whichthe biscuit is forced byinternalpressure. The step of forming the biscuit will now be described.

In "Fig. 1, I have illustrated four mold blocks'lO. eachihaving ageneral cavity 11.

'these blocks being mounted side by side in a suitable holder or basket.20. This basket is shown as a casting having a rectangular're cess inwhich the blocks are mounted, the blocks being held in the basket byscrews 21 passing; through the bottom of the basket.

The basket has the'face ot'lthe recess bottom planed off as shown at22and surrounded by .a. depression or groove 23. The blocks 10 are formedwith suitable .grooves across their bases, as indicated at13. Suitablevertical passageways 14 (Figs. 3 and extend from the cavities 11 throughthe block to the .grooveslS. .Thereare a number of these passagewaysselected at various points of the cavity as for example. one at each legand one for the head of the animal andperhaps two for the body, tl'ioughthe number may be varied as found most convenient. These passageways arepreferably made by drilliu from the bottom of the block with one drill.

almost to the cavity and then with a smaller drill into the cavity asshown inFig. 3.

It will be seen that the passageways and .groovesprovide a continuousconduit from thecavitiesllto the annular space 23 in the basket. Asuitable passageway coinmnnica'tcs with the annular space and isthreaded to receive an exhaust. pipe. By this means, the variouscavities may be exhausted of =air, so that a sheetof rubberlaid overthem is drawn down-into the cavities.

It is desirable to.pneumatically clamp the sheet over the various icavities before the rubber stock isseatedtherein, and during; the timeof such. seating, and the subsequent joiir ing operation, andI effectthis by making an annulargroove 26 about the face of the coinposite moldcommunicating bypassages Q7 with the suctiongroove J This convenient tomachine the groovefldpartly .intthe edge wall of the basket andpartly-in the upper "half in the blur on the floor of a rai It isconvenient also to half in the basket and ks. This is the coi'istructionshown in Figs. l. 2. and. il. The co-operating wold inenjibers(clesigna'ted in 7 Figs. 6 and "I l.) are suitably mourned. The resultis a simple and effective pneumatic mold for the sunultaneousmanufacture of a plu rality ot biscuits.

Each mold cavity it is surrmuided by raised cutting edge 15 with abeveled or rounded face. The combined cavity for the body of the articleis preferably divi ed equally by the plane of separz-itiou of the moldsbut in the cavities for the leg portions divergrefrom such plane. Thecutting edge shown in Figs. 1. 6 and 7. inplaii. but the peculiardeflection. thereof is most apparent in Figs. '10. it and 15. and willnow be fully described with particular reference to the latter figures.

The cavit es shown in Figs. 10 and ll are desigzned for the formation ofa biscuit which when vulcanized produces a toy horse. The cavitaccordino y has, beside the main body portion. four leg extensionsdesignated respcctivcly l( .'l7, l8 and 19. Flow. in one of the moldmembers. shown in Fig. '10. the

edge of the blocks. drill the openii extreme leg); cavities 16 and 19are located at elevations above the general plane of the body cavity,while the intermediate leg cavities l7 and 18 are below that plane. i

Tracing; the course of the cutting; cdaelo. that portion of the cutting;edge which e):- tends about the body of the animal from point a to pointZ) (with perhaps the e rception of the ear cavities) lies in a planeparallel with tbeface of the mold block. The cavities l6 and 19 arelocated on two plateaus above the plane of the body por- Now theintermediate leg}; cavities l7 and 1H lie in a dc ed region. or. oneought say.

with their cuttiiuqy edge, below the cuttin ("life about the bodr. Thus.the cutting}; ed 'e from about thepoinl 0 to the point f lies in aplane-similar to cutting edge from the point ,7 to the point 7t. whichis below that of the body portioi'i of the cutting edge 15. From thepoint k] to the point r the cutting edge descends rather al'vruptly. butalways at an incline and never taking a vertical drop. Frou'i the point7'', the cutting edge rises gradually and then descends to the point g.From the point 72.. the cuttii'ig' edge ri es rather steeply to aboutthe point 7' from which it passes while lviiur in the elevated plane tothe point then lron'i this point it descends to the point 7).

The course of the cutting edge just described is for one of the formingmold members--whether the upper or lower member is immaterial. Thecut-ting edge on the cooperating mold member shown in Fig. 11,con'iplenientary to that described. There, the cavities 17 and 18 forthe intermediate legs are located on a plateau while the extreinecavities 16 and 19 are located in a depressed region, and the cuttingedge on this mold. block rises at n from the leg cavity 19 to the bodycavity, COlIESPOIltliIlg' to the angle at which it fell between thepoint 7' and b in the block 10. Similar complementary variations arefound at 0, g, and r. i

By reason of the location of the leg cavities so that they are side byside, and the arrangement of the cutting edges to make a continuouscourse never passing behind itself or doubling too close to itself orchanging' too abruptly, I am able to seat the sheet rubber stockpneumatically in a warped condition over the combined cavities and incontact with the cutting edge throughout. Two sheets of stock are laidacross the respective cavities and suction applied by the exhaust pipes25, with the result that the sheet stock is held at the marginal groove26 about the set of cavities and is drawn down smoothly and evenly intoeach portion of the cavity and held taut across the continuous cuttingedge. Then when the two rubberlined mold members are brought together,and such. seated stock is joined between the beveled or rounded faces ofthe cutting edges to make a peripheral seam and at that time thestock iscut out from the two sheets, thus making a joined biscuit.

Before the junction, I may place in the lower rubliier-lining cavities asmall quantity of heat expanding substance, as for instance a mixture ofsodium nitrite ammonium chloride and water. Now the formed his cuit istransferred to a \uilcanizing, mold and heated to cure the rubber walland its seam as a. unit, and the same heat changes the internal mixtureto nitrogennnder pressure, sodium chloride and water. whereby it isforced a gainst the mold walls during curing", and thereafter remainspermanently inflated. Any other desired means, however, may be employedfor obtainingthe internal pressure and the ultimate inflation.

The vulcanizingr mold members 30 and 32 correspond a.pproxin'iately tothe forming; mold members, each having main cavity 31 and four leg);cavities. The latter, in the mold block 30, are designated 36, 37, 38and 39, and the corresponding cavities in the other mold block 32, aredesignated 36. etc. The arious leg cavities are positioned similarly tothose of the forming mold, that is to say, the cavities 36 and 39 are ona plateau, and the cavities 37 and 38 on the floor of a. valley, in ablock of Fig. 12, while the cavities 36 and 39* are in a depressedregion, and the cavities 87 and 88 are on a plateau in. the block 32 ofFig. 13. While the vulcanizing mold cavities conform, in general, tothose of the forming; mold, they have various refinements to give thedesired finished form to the article, shown in Figs. 12 and 13.

An important difference between the forming mold and the curing mold isthat the forming mold has the continuous raised cut ting edge about thecavities, whereas, the

curing mold has flat horizontal surfaces about the cavities. As shown,these surfaces are the general planes of the mold in Figs. 12 and 13,the flat plateau surfaces 6' and u and the flat depressed surface o inFig. 12, and the complementary depressed flat surfaces to and a", andraised flat surface y, in Fig. 13.

The various flat surfaces of the two curing mold members 30 and 32 cometightly to get-her when the molds are closed as shown in Fig. 17, thusconfining the biscuit during vulcanization. The biscuit as made by theforming mold as indicated in Fig. 14 comprises a main body portion A andleg, extensions 3, C. D and E, all joined by a peripheral seam F whichmay take substantially the course indicated in 14-. l dhen such biscuitis transferred to the curing mold and cured, the originally formed scan.is lost to view, but a slight tin may develop at the meeting face of thecuring: mold meml'iers, this fin being readily buffed off after thearticle is cured.

From the foregoingdeseription, it will be seen that. my invention iswell adapted for the fori'nation pneui'natically from sheet stock ofhollow rubber articles representing toy animals, whcrein the planespassing through the leg portions are not the same as the planes passingthrough the seam of the body portion. It will further be seen thathollow rubber articles having these characteristics may thus be madewith. only forming and. viilcaniziiig operations, that the cost isgreatly reduced over the old dieing process, and the speed of productiongreatly increased.

I claim:

1. An apparatus for forn'iing hollow articles of plastic n'iat-erial.comprising a, mold cavity embraced by a cutting edge having itscuttii'ig face diverted from a single plane, and a, cooperating moldcavity en'ibraced by a diverted cutting edge complen'ientary to thefirst mentioned edge.

2. An apparatus for making hollow articles of plastic materialcomprising means for pneun'iatically seating; two sheets of stock in.two cooperating cavities, each surrounded by a raised cutting: edgewhich in certain regions is diverted up or down from a single plane, thediversion in the two mold memconnected by rau'ips,

hers bein isubstantiall i 'ecual. in de 'ree and wngposite in directionand always less than 90;ln'inging the lined cavities together to jointhe stock by a surrounding seam.

An appars us for forming hollow articles of plastic material comprisingmeans 'forseating by suction a sheet of stockina mold cavity whichtevninates in a continuous cutting edge having its face lying at variouselevations, means for seating in similar manner another sheet of stockin a co operating mold cavity wlnch terminates in a continuous cuttingedge lying at various elevations which are complementary to the firstmentioned planes, whereby when the horizontal plane while the legportions are sunk "from various planes complementary in the. two mold.members, each moldmember l'iuviiig a leg cavity above the horizontalplaneand a leg cavity aclow such plane and the combined cavity of eachmember being si-irrounded by a continuous raised cutting edge the top otwhich is deflected from a single plane, whereby when such rubber linedmold meinbers'are brought together a seam is torn'ied and the surplusstock is cut off, and means for thereafter vu-lcanizing the biscuit thuformed.

5. An apparatus for making hollow rubber articles comprising means forseating a sheet of stock in a multiple part cavity having ditlercntparts at different elevations and the complete cavity embrac d by acutting edge having its face lying in various planes, means :lo-rseating another sheet of stock a cooperating mold carity whichterminates in an en'ibracing cutting edge complcmcntary to the firstmentioned, the two rubber lined cavities being adapted to hebroughttogether to join the two sheets and cut oil the surplus stockabout the biscuit thus torn'icd, and means tor thereafter curing thebiscuit.

('3. An apparatus for making hollow articles oi plastic material compri1' means for seating by suction two sheets o'l stock in two cooperatingcavities, each cavity having one portion at a diii'orent elevation fromanother portion, the elevations being relatively complementary in thetwo cavities, and each; cavity being surrounded by a raised 'cul'ling ore which in certain regions is deflected tr in a horizontal plane, thede'tiection in the two mold members being at tan tially equal indcgreeand opposite in d1rection, the two lined cavities being adapted to bebroughttogether to join the stock by a surrounding seam.

7..An apparatus for forming hollow ar ticles of plastic materialcomprisii means for penumatically seating a sheet or stock in a moldcavity whichteri'uinates in an emln'acing cutting edge which lies invarious stock.

An apparatus forinaking hollow rubber articles having legs comprisingmeans tor pneumatically seating two sheets otrubber stock in twocavitary mold members, the cavities in the two members having similarbodyportionssunk from substantially a horizontal plane and having a legcavity above the horizontal plane and a leg cavity below such plane, thecombined cavity-0t each member being surrounded by a continuous raisedcutting edge, which passes from one elevation to another by ramps,bringing the two rubber-lined mold menibers together to form a seam andcut off the surplus stock and means for thereafter vulcanizino; thebiscuit thus formed.

9. The moldfor forming hollow articles of plastic material comprisingtwo members each having a cavity which terminatcs'in a continuous raisedcutting edge lying at various elevations connectedby ramps thc cuttingedge on one mold member being coinpleincntary to the other, andpassageways leading from the cavities, whereby the air may be exhaustedtherefrom.

10. A mold for making hollow articles of plastic-material comprising ablock having therein a cavity with parts of its rim at differentelevations, a warped raised cutting edge embracing the cavity and'a ventlead ing from the cavity.

11. A mold for making hollow articles comprising a basket having asupporting floor with a groove about it, aseries of mold blocks in thebasket resting'on said floor, each block having a groove in its bottomadapted to be in communication with this groove in the basket, and aneduction passageway communicating with thelatter groove.

havin a cavit i in its uwer taco a roove ill in its lower face, and apassageway from the last mentioned groove to the cavity, said lastmentioned groove being in communication with the first mentioned groove.

13. A mold for making hollow articles comprising a Tasting having arectangular recess therein, a series ot rectangular mold blocks side byside in said recess, resting on the floor thereof, a groove in saidfloor beneath the mold blocks, a passageway leading from said groove, agroove in the base of each mold block a cavity in the face of each moldblock, and a passageway in each mold block from the face cavity to thebase groove thereof, said base grooves of the blocks being adapted tocommunicate with the floor groove of the basket.

14:. The method of making articles of plastic material, comprisingseating a sheet of stock with that region which is to form the junctionwith other stock distorted from a single plane, seating another sheetwith its junction portion compleInenta-rily distorted, joining the twosheets at such distorted regions and simultaneously cutting through thesheets just outside of the junction.

15. The method of making articles of plastic material, comprisingpneumatically seating a sheet of stock in such manner that a circuitousportion is distorted from a single plane, pneumatically seating anothersheet with a corresponding circuitous portion coinplementarily distortedfrom a single plane, and bringing such two seated sheets together tojoin them at the distorted regions and at the same time cutting throughthem just outside of the junction.

16. The method of making hollow rubber articles comprising seating asheet of stock by suction in a cavity the edge of which is distortedfrom a single plane in the region which is to form the junction, seatinganother sheet by suction with its junctionportion complementarilydistorted, thereafter joining the two sheets and at the same timecutting through them just outside the junction, then removing the joinedarticle from its cavities and thereafter vulcanizing it in cavitieshaving an undulating meeting surface.

In testimony whereof, I hereunto aflix my si gn atu re.

JAMES SGHAEFER.

